1. Field of the Invention
This invention relates to the production of cased books formed with cores of apertured sheets and end sheets bound together by thin, narrow plastic binding strips. The core is cased in a case which has a wide pressure-sensitive strip extending from the middle of the spine out preferably to the inner edge of the Davey boards used to stiffen the covers. The preferred apparatus for casing the book is characterized by two features, one being that when the spine edge of the core is pivoted down to contact with the pressure-sensitive spine strip, the spine area is depressed below the surface of the platens which support the case, whereupon the platens are moved inward, crimping the pressure-sensitive strip against the end sheets considerably more effectively than in prior constructions of this general type. A second feature of the apparatus is the provision of means for rolling a crease into the side of the book immediately inward of the Davey boards and outwardly of the plastic binding strips which secure the core.
2. Reference to Related Art
Casing-in machines of this general type are illustrated in U.S. Pat. Nos. 3,825,963 and 3,825,964, as well as U.S. Pat. No. 236,373. The present invention comprises an improvement on such machines.
Additionally, since the issuance of the aforesaid patents, improvements have been made on the commercial machines sold prior to the present invention. For example, an adjustment knob for moving the platens which support the case inward and outward has been located on the side of the machine and means for moving the platens inward and outward has also been changed. The present invention incorporates some of these modifications.
Case constructions of the prior art are illustrated in U.S. Pat. No. 3,859,963, as well as U.S. Pat. Nos. 3,730,566, and 4,570,351. In general, the improvement of the present invention relates to the spine area. No foam padding behind the pressure-sensitive adhesive is employed in accordance with the present invention, but the pressure-sensitive adhesive is adhered directly to the inside of the spine cover of the book. The pressure-sensitive strip used with the present invention is considerably wider than those heretofore employed so that, not only does the spine strip cover the spine of the core and the plastic binding strips thereof, but also extends outward to the area of the core outside the spine area and preferably to the inner edge of the Davey board used to stiffen the cover of the case. In those instances where a stiffener such as Davey board is not used, the spine strip is preferably equally wide. Thus as a practical rule of thumb, the pressure-sensitive spine strip is approximately 11/2 inches wider than the spine of the core with which it is to be used.
End sheets used with the present invention are shown in U.S. Pat. Nos. 3,749,422 and 3,749,423. The end sheets are bound along with the sheets of the book into the core by the use of plastic binding strips such as those shown in FIG. 1 of U.S. Pat. No. 4,369,013. It will be understood that other binding strips may be used. The end sheets are covered with pressure-sensitive adhesive on their outer faces and are protected initially by release paper. One of the features of the present invention is the fact that the pressure-sensitive spine strip is caused firmly to adhere to the end sheets so that a superior binding is achieved.